!(function () {

    // alignment pattern
    var adelta = [
      0, 11, 15, 19, 23, 27, 31,
      16, 18, 20, 22, 24, 26, 28, 20, 22, 24, 24, 26, 28, 28, 22, 24, 24,
      26, 26, 28, 28, 24, 24, 26, 26, 26, 28, 28, 24, 26, 26, 26, 28, 28
    ];
  
    // version block
    var vpat = [
      0xc94, 0x5bc, 0xa99, 0x4d3, 0xbf6, 0x762, 0x847, 0x60d,
      0x928, 0xb78, 0x45d, 0xa17, 0x532, 0x9a6, 0x683, 0x8c9,
      0x7ec, 0xec4, 0x1e1, 0xfab, 0x08e, 0xc1a, 0x33f, 0xd75,
      0x250, 0x9d5, 0x6f0, 0x8ba, 0x79f, 0xb0b, 0x42e, 0xa64,
      0x541, 0xc69
    ];
  
    // final format bits with mask: level << 3 | mask
    var fmtword = [
      0x77c4, 0x72f3, 0x7daa, 0x789d, 0x662f, 0x6318, 0x6c41, 0x6976,    //L
      0x5412, 0x5125, 0x5e7c, 0x5b4b, 0x45f9, 0x40ce, 0x4f97, 0x4aa0,    //M
      0x355f, 0x3068, 0x3f31, 0x3a06, 0x24b4, 0x2183, 0x2eda, 0x2bed,    //Q
      0x1689, 0x13be, 0x1ce7, 0x19d0, 0x0762, 0x0255, 0x0d0c, 0x083b    //H
    ];
  
    // 4 per version: number of blocks 1,2; data width; ecc width
    var eccblocks = [
      1, 0, 19, 7, 1, 0, 16, 10, 1, 0, 13, 13, 1, 0, 9, 17,
      1, 0, 34, 10, 1, 0, 28, 16, 1, 0, 22, 22, 1, 0, 16, 28,
      1, 0, 55, 15, 1, 0, 44, 26, 2, 0, 17, 18, 2, 0, 13, 22,
      1, 0, 80, 20, 2, 0, 32, 18, 2, 0, 24, 26, 4, 0, 9, 16,
      1, 0, 108, 26, 2, 0, 43, 24, 2, 2, 15, 18, 2, 2, 11, 22,
      2, 0, 68, 18, 4, 0, 27, 16, 4, 0, 19, 24, 4, 0, 15, 28,
      2, 0, 78, 20, 4, 0, 31, 18, 2, 4, 14, 18, 4, 1, 13, 26,
      2, 0, 97, 24, 2, 2, 38, 22, 4, 2, 18, 22, 4, 2, 14, 26,
      2, 0, 116, 30, 3, 2, 36, 22, 4, 4, 16, 20, 4, 4, 12, 24,
      2, 2, 68, 18, 4, 1, 43, 26, 6, 2, 19, 24, 6, 2, 15, 28,
      4, 0, 81, 20, 1, 4, 50, 30, 4, 4, 22, 28, 3, 8, 12, 24,
      2, 2, 92, 24, 6, 2, 36, 22, 4, 6, 20, 26, 7, 4, 14, 28,
      4, 0, 107, 26, 8, 1, 37, 22, 8, 4, 20, 24, 12, 4, 11, 22,
      3, 1, 115, 30, 4, 5, 40, 24, 11, 5, 16, 20, 11, 5, 12, 24,
      5, 1, 87, 22, 5, 5, 41, 24, 5, 7, 24, 30, 11, 7, 12, 24,
      5, 1, 98, 24, 7, 3, 45, 28, 15, 2, 19, 24, 3, 13, 15, 30,
      1, 5, 107, 28, 10, 1, 46, 28, 1, 15, 22, 28, 2, 17, 14, 28,
      5, 1, 120, 30, 9, 4, 43, 26, 17, 1, 22, 28, 2, 19, 14, 28,
      3, 4, 113, 28, 3, 11, 44, 26, 17, 4, 21, 26, 9, 16, 13, 26,
      3, 5, 107, 28, 3, 13, 41, 26, 15, 5, 24, 30, 15, 10, 15, 28,
      4, 4, 116, 28, 17, 0, 42, 26, 17, 6, 22, 28, 19, 6, 16, 30,
      2, 7, 111, 28, 17, 0, 46, 28, 7, 16, 24, 30, 34, 0, 13, 24,
      4, 5, 121, 30, 4, 14, 47, 28, 11, 14, 24, 30, 16, 14, 15, 30,
      6, 4, 117, 30, 6, 14, 45, 28, 11, 16, 24, 30, 30, 2, 16, 30,
      8, 4, 106, 26, 8, 13, 47, 28, 7, 22, 24, 30, 22, 13, 15, 30,
      10, 2, 114, 28, 19, 4, 46, 28, 28, 6, 22, 28, 33, 4, 16, 30,
      8, 4, 122, 30, 22, 3, 45, 28, 8, 26, 23, 30, 12, 28, 15, 30,
      3, 10, 117, 30, 3, 23, 45, 28, 4, 31, 24, 30, 11, 31, 15, 30,
      7, 7, 116, 30, 21, 7, 45, 28, 1, 37, 23, 30, 19, 26, 15, 30,
      5, 10, 115, 30, 19, 10, 47, 28, 15, 25, 24, 30, 23, 25, 15, 30,
      13, 3, 115, 30, 2, 29, 46, 28, 42, 1, 24, 30, 23, 28, 15, 30,
      17, 0, 115, 30, 10, 23, 46, 28, 10, 35, 24, 30, 19, 35, 15, 30,
      17, 1, 115, 30, 14, 21, 46, 28, 29, 19, 24, 30, 11, 46, 15, 30,
      13, 6, 115, 30, 14, 23, 46, 28, 44, 7, 24, 30, 59, 1, 16, 30,
      12, 7, 121, 30, 12, 26, 47, 28, 39, 14, 24, 30, 22, 41, 15, 30,
      6, 14, 121, 30, 6, 34, 47, 28, 46, 10, 24, 30, 2, 64, 15, 30,
      17, 4, 122, 30, 29, 14, 46, 28, 49, 10, 24, 30, 24, 46, 15, 30,
      4, 18, 122, 30, 13, 32, 46, 28, 48, 14, 24, 30, 42, 32, 15, 30,
      20, 4, 117, 30, 40, 7, 47, 28, 43, 22, 24, 30, 10, 67, 15, 30,
      19, 6, 118, 30, 18, 31, 47, 28, 34, 34, 24, 30, 20, 61, 15, 30
    ];
  
    // Galois field log table
    var glog = [
      0xff, 0x00, 0x01, 0x19, 0x02, 0x32, 0x1a, 0xc6, 0x03, 0xdf, 0x33, 0xee, 0x1b, 0x68, 0xc7, 0x4b,
      0x04, 0x64, 0xe0, 0x0e, 0x34, 0x8d, 0xef, 0x81, 0x1c, 0xc1, 0x69, 0xf8, 0xc8, 0x08, 0x4c, 0x71,
      0x05, 0x8a, 0x65, 0x2f, 0xe1, 0x24, 0x0f, 0x21, 0x35, 0x93, 0x8e, 0xda, 0xf0, 0x12, 0x82, 0x45,
      0x1d, 0xb5, 0xc2, 0x7d, 0x6a, 0x27, 0xf9, 0xb9, 0xc9, 0x9a, 0x09, 0x78, 0x4d, 0xe4, 0x72, 0xa6,
      0x06, 0xbf, 0x8b, 0x62, 0x66, 0xdd, 0x30, 0xfd, 0xe2, 0x98, 0x25, 0xb3, 0x10, 0x91, 0x22, 0x88,
      0x36, 0xd0, 0x94, 0xce, 0x8f, 0x96, 0xdb, 0xbd, 0xf1, 0xd2, 0x13, 0x5c, 0x83, 0x38, 0x46, 0x40,
      0x1e, 0x42, 0xb6, 0xa3, 0xc3, 0x48, 0x7e, 0x6e, 0x6b, 0x3a, 0x28, 0x54, 0xfa, 0x85, 0xba, 0x3d,
      0xca, 0x5e, 0x9b, 0x9f, 0x0a, 0x15, 0x79, 0x2b, 0x4e, 0xd4, 0xe5, 0xac, 0x73, 0xf3, 0xa7, 0x57,
      0x07, 0x70, 0xc0, 0xf7, 0x8c, 0x80, 0x63, 0x0d, 0x67, 0x4a, 0xde, 0xed, 0x31, 0xc5, 0xfe, 0x18,
      0xe3, 0xa5, 0x99, 0x77, 0x26, 0xb8, 0xb4, 0x7c, 0x11, 0x44, 0x92, 0xd9, 0x23, 0x20, 0x89, 0x2e,
      0x37, 0x3f, 0xd1, 0x5b, 0x95, 0xbc, 0xcf, 0xcd, 0x90, 0x87, 0x97, 0xb2, 0xdc, 0xfc, 0xbe, 0x61,
      0xf2, 0x56, 0xd3, 0xab, 0x14, 0x2a, 0x5d, 0x9e, 0x84, 0x3c, 0x39, 0x53, 0x47, 0x6d, 0x41, 0xa2,
      0x1f, 0x2d, 0x43, 0xd8, 0xb7, 0x7b, 0xa4, 0x76, 0xc4, 0x17, 0x49, 0xec, 0x7f, 0x0c, 0x6f, 0xf6,
      0x6c, 0xa1, 0x3b, 0x52, 0x29, 0x9d, 0x55, 0xaa, 0xfb, 0x60, 0x86, 0xb1, 0xbb, 0xcc, 0x3e, 0x5a,
      0xcb, 0x59, 0x5f, 0xb0, 0x9c, 0xa9, 0xa0, 0x51, 0x0b, 0xf5, 0x16, 0xeb, 0x7a, 0x75, 0x2c, 0xd7,
      0x4f, 0xae, 0xd5, 0xe9, 0xe6, 0xe7, 0xad, 0xe8, 0x74, 0xd6, 0xf4, 0xea, 0xa8, 0x50, 0x58, 0xaf
    ];
  
    // Galios field exponent table
    var gexp = [
      0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1d, 0x3a, 0x74, 0xe8, 0xcd, 0x87, 0x13, 0x26,
      0x4c, 0x98, 0x2d, 0x5a, 0xb4, 0x75, 0xea, 0xc9, 0x8f, 0x03, 0x06, 0x0c, 0x18, 0x30, 0x60, 0xc0,
      0x9d, 0x27, 0x4e, 0x9c, 0x25, 0x4a, 0x94, 0x35, 0x6a, 0xd4, 0xb5, 0x77, 0xee, 0xc1, 0x9f, 0x23,
      0x46, 0x8c, 0x05, 0x0a, 0x14, 0x28, 0x50, 0xa0, 0x5d, 0xba, 0x69, 0xd2, 0xb9, 0x6f, 0xde, 0xa1,
      0x5f, 0xbe, 0x61, 0xc2, 0x99, 0x2f, 0x5e, 0xbc, 0x65, 0xca, 0x89, 0x0f, 0x1e, 0x3c, 0x78, 0xf0,
      0xfd, 0xe7, 0xd3, 0xbb, 0x6b, 0xd6, 0xb1, 0x7f, 0xfe, 0xe1, 0xdf, 0xa3, 0x5b, 0xb6, 0x71, 0xe2,
      0xd9, 0xaf, 0x43, 0x86, 0x11, 0x22, 0x44, 0x88, 0x0d, 0x1a, 0x34, 0x68, 0xd0, 0xbd, 0x67, 0xce,
      0x81, 0x1f, 0x3e, 0x7c, 0xf8, 0xed, 0xc7, 0x93, 0x3b, 0x76, 0xec, 0xc5, 0x97, 0x33, 0x66, 0xcc,
      0x85, 0x17, 0x2e, 0x5c, 0xb8, 0x6d, 0xda, 0xa9, 0x4f, 0x9e, 0x21, 0x42, 0x84, 0x15, 0x2a, 0x54,
      0xa8, 0x4d, 0x9a, 0x29, 0x52, 0xa4, 0x55, 0xaa, 0x49, 0x92, 0x39, 0x72, 0xe4, 0xd5, 0xb7, 0x73,
      0xe6, 0xd1, 0xbf, 0x63, 0xc6, 0x91, 0x3f, 0x7e, 0xfc, 0xe5, 0xd7, 0xb3, 0x7b, 0xf6, 0xf1, 0xff,
      0xe3, 0xdb, 0xab, 0x4b, 0x96, 0x31, 0x62, 0xc4, 0x95, 0x37, 0x6e, 0xdc, 0xa5, 0x57, 0xae, 0x41,
      0x82, 0x19, 0x32, 0x64, 0xc8, 0x8d, 0x07, 0x0e, 0x1c, 0x38, 0x70, 0xe0, 0xdd, 0xa7, 0x53, 0xa6,
      0x51, 0xa2, 0x59, 0xb2, 0x79, 0xf2, 0xf9, 0xef, 0xc3, 0x9b, 0x2b, 0x56, 0xac, 0x45, 0x8a, 0x09,
      0x12, 0x24, 0x48, 0x90, 0x3d, 0x7a, 0xf4, 0xf5, 0xf7, 0xf3, 0xfb, 0xeb, 0xcb, 0x8b, 0x0b, 0x16,
      0x2c, 0x58, 0xb0, 0x7d, 0xfa, 0xe9, 0xcf, 0x83, 0x1b, 0x36, 0x6c, 0xd8, 0xad, 0x47, 0x8e, 0x00
    ];
  
    // Working buffers:
    // data input and ecc append, image working buffer, fixed part of image, run lengths for badness
    var strinbuf = [], eccbuf = [], qrframe = [], framask = [], rlens = [];
    // Control values - width is based on version, last 4 are from table.
    var version, width, neccblk1, neccblk2, datablkw, eccblkwid;
    var ecclevel = 2;
    // set bit to indicate cell in qrframe is immutable.  symmetric around diagonal
    function setmask(x, y) {
      var bt;
      if (x > y) {
        bt = x;
        x = y;
        y = bt;
      }
      // y*y = 1+3+5...
      bt = y;
      bt *= y;
      bt += y;
      bt >>= 1;
      bt += x;
      framask[bt] = 1;
    }
  
    // enter alignment pattern - black to qrframe, white to mask (later black frame merged to mask)
    function putalign(x, y) {
      var j;
  
      qrframe[x + width * y] = 1;
      for (j = -2; j < 2; j++) {
        qrframe[(x + j) + width * (y - 2)] = 1;
        qrframe[(x - 2) + width * (y + j + 1)] = 1;
        qrframe[(x + 2) + width * (y + j)] = 1;
        qrframe[(x + j + 1) + width * (y + 2)] = 1;
      }
      for (j = 0; j < 2; j++) {
        setmask(x - 1, y + j);
        setmask(x + 1, y - j);
        setmask(x - j, y - 1);
        setmask(x + j, y + 1);
      }
    }
  
    //========================================================================
    // Reed Solomon error correction
    // exponentiation mod N
    function modnn(x) {
      while (x >= 255) {
        x -= 255;
        x = (x >> 8) + (x & 255);
      }
      return x;
    }
  
    var genpoly = [];
  
    // Calculate and append ECC data to data block.  Block is in strinbuf, indexes to buffers given.
    function appendrs(data, dlen, ecbuf, eclen) {
      var i, j, fb;
  
      for (i = 0; i < eclen; i++)
        strinbuf[ecbuf + i] = 0;
      for (i = 0; i < dlen; i++) {
        fb = glog[strinbuf[data + i] ^ strinbuf[ecbuf]];
        if (fb != 255)     /* fb term is non-zero */
          for (j = 1; j < eclen; j++)
            strinbuf[ecbuf + j - 1] = strinbuf[ecbuf + j] ^ gexp[modnn(fb + genpoly[eclen - j])];
        else
          for (j = ecbuf; j < ecbuf + eclen; j++)
            strinbuf[j] = strinbuf[j + 1];
        strinbuf[ecbuf + eclen - 1] = fb == 255 ? 0 : gexp[modnn(fb + genpoly[0])];
      }
    }
  
    //========================================================================
    // Frame data insert following the path rules
  
    // check mask - since symmetrical use half.
    function ismasked(x, y) {
      var bt;
      if (x > y) {
        bt = x;
        x = y;
        y = bt;
      }
      bt = y;
      bt += y * y;
      bt >>= 1;
      bt += x;
      return framask[bt];
    }
  
    //========================================================================
    //  Apply the selected mask out of the 8.
    function applymask(m) {
      var x, y, r3x, r3y;
  
      switch (m) {
        case 0:
          for (y = 0; y < width; y++)
            for (x = 0; x < width; x++)
              if (!((x + y) & 1) && !ismasked(x, y))
                qrframe[x + y * width] ^= 1;
          break;
        case 1:
          for (y = 0; y < width; y++)
            for (x = 0; x < width; x++)
              if (!(y & 1) && !ismasked(x, y))
                qrframe[x + y * width] ^= 1;
          break;
        case 2:
          for (y = 0; y < width; y++)
            for (r3x = 0, x = 0; x < width; x++ , r3x++) {
              if (r3x == 3)
                r3x = 0;
              if (!r3x && !ismasked(x, y))
                qrframe[x + y * width] ^= 1;
            }
          break;
        case 3:
          for (r3y = 0, y = 0; y < width; y++ , r3y++) {
            if (r3y == 3)
              r3y = 0;
            for (r3x = r3y, x = 0; x < width; x++ , r3x++) {
              if (r3x == 3)
                r3x = 0;
              if (!r3x && !ismasked(x, y))
                qrframe[x + y * width] ^= 1;
            }
          }
          break;
        case 4:
          for (y = 0; y < width; y++)
            for (r3x = 0, r3y = ((y >> 1) & 1), x = 0; x < width; x++ , r3x++) {
              if (r3x == 3) {
                r3x = 0;
                r3y = !r3y;
              }
              if (!r3y && !ismasked(x, y))
                qrframe[x + y * width] ^= 1;
            }
          break;
        case 5:
          for (r3y = 0, y = 0; y < width; y++ , r3y++) {
            if (r3y == 3)
              r3y = 0;
            for (r3x = 0, x = 0; x < width; x++ , r3x++) {
              if (r3x == 3)
                r3x = 0;
              if (!((x & y & 1) + !(!r3x | !r3y)) && !ismasked(x, y))
                qrframe[x + y * width] ^= 1;
            }
          }
          break;
        case 6:
          for (r3y = 0, y = 0; y < width; y++ , r3y++) {
            if (r3y == 3)
              r3y = 0;
            for (r3x = 0, x = 0; x < width; x++ , r3x++) {
              if (r3x == 3)
                r3x = 0;
              if (!(((x & y & 1) + (r3x && (r3x == r3y))) & 1) && !ismasked(x, y))
                qrframe[x + y * width] ^= 1;
            }
          }
          break;
        case 7:
          for (r3y = 0, y = 0; y < width; y++ , r3y++) {
            if (r3y == 3)
              r3y = 0;
            for (r3x = 0, x = 0; x < width; x++ , r3x++) {
              if (r3x == 3)
                r3x = 0;
              if (!(((r3x && (r3x == r3y)) + ((x + y) & 1)) & 1) && !ismasked(x, y))
                qrframe[x + y * width] ^= 1;
            }
          }
          break;
      }
      return;
    }
  
    // Badness coefficients.
    var N1 = 3, N2 = 3, N3 = 40, N4 = 10;
  
    // Using the table of the length of each run, calculate the amount of bad image 
    // - long runs or those that look like finders; called twice, once each for X and Y
    function badruns(length) {
      var i;
      var runsbad = 0;
      for (i = 0; i <= length; i++)
        if (rlens[i] >= 5)
          runsbad += N1 + rlens[i] - 5;
      // BwBBBwB as in finder
      for (i = 3; i < length - 1; i += 2)
        if (rlens[i - 2] == rlens[i + 2]
          && rlens[i + 2] == rlens[i - 1]
          && rlens[i - 1] == rlens[i + 1]
          && rlens[i - 1] * 3 == rlens[i]
          // white around the black pattern? Not part of spec
          && (rlens[i - 3] == 0 // beginning
            || i + 3 > length  // end
            || rlens[i - 3] * 3 >= rlens[i] * 4 || rlens[i + 3] * 3 >= rlens[i] * 4)
        )
          runsbad += N3;
      return runsbad;
    }
  
    // Calculate how bad the masked image is - blocks, imbalance, runs, or finders.
    function badcheck() {
      var x, y, h, b, b1;
      var thisbad = 0;
      var bw = 0;
  
      // blocks of same color.
      for (y = 0; y < width - 1; y++)
        for (x = 0; x < width - 1; x++)
          if ((qrframe[x + width * y] && qrframe[(x + 1) + width * y]
            && qrframe[x + width * (y + 1)] && qrframe[(x + 1) + width * (y + 1)]) // all black
            || !(qrframe[x + width * y] || qrframe[(x + 1) + width * y]
              || qrframe[x + width * (y + 1)] || qrframe[(x + 1) + width * (y + 1)])) // all white
            thisbad += N2;
  
      // X runs
      for (y = 0; y < width; y++) {
        rlens[0] = 0;
        for (h = b = x = 0; x < width; x++) {
          if ((b1 = qrframe[x + width * y]) == b)
            rlens[h]++;
          else
            rlens[++h] = 1;
          b = b1;
          bw += b ? 1 : -1;
        }
        thisbad += badruns(h);
      }
  
      // black/white imbalance
      if (bw < 0)
        bw = -bw;
  
      var big = bw;
      var count = 0;
      big += big << 2;
      big <<= 1;
      while (big > width * width)
        big -= width * width, count++;
      thisbad += count * N4;
  
      // Y runs
      for (x = 0; x < width; x++) {
        rlens[0] = 0;
        for (h = b = y = 0; y < width; y++) {
          if ((b1 = qrframe[x + width * y]) == b)
            rlens[h]++;
          else
            rlens[++h] = 1;
          b = b1;
        }
        thisbad += badruns(h);
      }
      return thisbad;
    }
  
    function genframe(instring) {
      var x, y, k, t, v, i, j, m;
  
      // find the smallest version that fits the string
      t = instring.length;
      version = 0;
      do {
        version++;
        k = (ecclevel - 1) * 4 + (version - 1) * 16;
        neccblk1 = eccblocks[k++];
        neccblk2 = eccblocks[k++];
        datablkw = eccblocks[k++];
        eccblkwid = eccblocks[k];
        k = datablkw * (neccblk1 + neccblk2) + neccblk2 - 3 + (version <= 9);
        if (t <= k)
          break;
      } while (version < 40);
  
      // FIXME - insure that it fits insted of being truncated
      width = 17 + 4 * version;
  
      // allocate, clear and setup data structures
      v = datablkw + (datablkw + eccblkwid) * (neccblk1 + neccblk2) + neccblk2;
      for (t = 0; t < v; t++)
        eccbuf[t] = 0;
      strinbuf = instring.slice(0);
  
      for (t = 0; t < width * width; t++)
        qrframe[t] = 0;
  
      for (t = 0; t < (width * (width + 1) + 1) / 2; t++)
        framask[t] = 0;
  
      // insert finders - black to frame, white to mask
      for (t = 0; t < 3; t++) {
        k = 0;
        y = 0;
        if (t == 1)
          k = (width - 7);
        if (t == 2)
          y = (width - 7);
        qrframe[(y + 3) + width * (k + 3)] = 1;
        for (x = 0; x < 6; x++) {
          qrframe[(y + x) + width * k] = 1;
          qrframe[y + width * (k + x + 1)] = 1;
          qrframe[(y + 6) + width * (k + x)] = 1;
          qrframe[(y + x + 1) + width * (k + 6)] = 1;
        }
        for (x = 1; x < 5; x++) {
          setmask(y + x, k + 1);
          setmask(y + 1, k + x + 1);
          setmask(y + 5, k + x);
          setmask(y + x + 1, k + 5);
        }
        for (x = 2; x < 4; x++) {
          qrframe[(y + x) + width * (k + 2)] = 1;
          qrframe[(y + 2) + width * (k + x + 1)] = 1;
          qrframe[(y + 4) + width * (k + x)] = 1;
          qrframe[(y + x + 1) + width * (k + 4)] = 1;
        }
      }
  
      // alignment blocks
      if (version > 1) {
        t = adelta[version];
        y = width - 7;
        for (; ;) {
          x = width - 7;
          while (x > t - 3) {
            putalign(x, y);
            if (x < t)
              break;
            x -= t;
          }
          if (y <= t + 9)
            break;
          y -= t;
          putalign(6, y);
          putalign(y, 6);
        }
      }
  
      // single black
      qrframe[8 + width * (width - 8)] = 1;
  
      // timing gap - mask only
      for (y = 0; y < 7; y++) {
        setmask(7, y);
        setmask(width - 8, y);
        setmask(7, y + width - 7);
      }
      for (x = 0; x < 8; x++) {
        setmask(x, 7);
        setmask(x + width - 8, 7);
        setmask(x, width - 8);
      }
  
      // reserve mask-format area
      for (x = 0; x < 9; x++)
        setmask(x, 8);
      for (x = 0; x < 8; x++) {
        setmask(x + width - 8, 8);
        setmask(8, x);
      }
      for (y = 0; y < 7; y++)
        setmask(8, y + width - 7);
  
      // timing row/col
      for (x = 0; x < width - 14; x++)
        if (x & 1) {
          setmask(8 + x, 6);
          setmask(6, 8 + x);
        }
        else {
          qrframe[(8 + x) + width * 6] = 1;
          qrframe[6 + width * (8 + x)] = 1;
        }
  
      // version block
      if (version > 6) {
        t = vpat[version - 7];
        k = 17;
        for (x = 0; x < 6; x++)
          for (y = 0; y < 3; y++ , k--)
            if (1 & (k > 11 ? version >> (k - 12) : t >> k)) {
              qrframe[(5 - x) + width * (2 - y + width - 11)] = 1;
              qrframe[(2 - y + width - 11) + width * (5 - x)] = 1;
            }
            else {
              setmask(5 - x, 2 - y + width - 11);
              setmask(2 - y + width - 11, 5 - x);
            }
      }
  
      // sync mask bits - only set above for white spaces, so add in black bits
      for (y = 0; y < width; y++)
        for (x = 0; x <= y; x++)
          if (qrframe[x + width * y])
            setmask(x, y);
  
      // convert string to bitstream
      // 8 bit data to QR-coded 8 bit data (numeric or alphanum, or kanji not supported)
      v = strinbuf.length;
  
      // string to array
      for (i = 0; i < v; i++)
        eccbuf[i] = strinbuf.charCodeAt(i);
      strinbuf = eccbuf.slice(0);
  
      // calculate max string length
      x = datablkw * (neccblk1 + neccblk2) + neccblk2;
      if (v >= x - 2) {
        v = x - 2;
        if (version > 9)
          v--;
      }
  
      // shift and repack to insert length prefix
      i = v;
      if (version > 9) {
        strinbuf[i + 2] = 0;
        strinbuf[i + 3] = 0;
        while (i--) {
          t = strinbuf[i];
          strinbuf[i + 3] |= 255 & (t << 4);
          strinbuf[i + 2] = t >> 4;
        }
        strinbuf[2] |= 255 & (v << 4);
        strinbuf[1] = v >> 4;
        strinbuf[0] = 0x40 | (v >> 12);
      }
      else {
        strinbuf[i + 1] = 0;
        strinbuf[i + 2] = 0;
        while (i--) {
          t = strinbuf[i];
          strinbuf[i + 2] |= 255 & (t << 4);
          strinbuf[i + 1] = t >> 4;
        }
        strinbuf[1] |= 255 & (v << 4);
        strinbuf[0] = 0x40 | (v >> 4);
      }
      // fill to end with pad pattern
      i = v + 3 - (version < 10);
      while (i < x) {
        strinbuf[i++] = 0xec;
        // buffer has room    if (i == x)      break;
        strinbuf[i++] = 0x11;
      }
  
      // calculate and append ECC
  
      // calculate generator polynomial
      genpoly[0] = 1;
      for (i = 0; i < eccblkwid; i++) {
        genpoly[i + 1] = 1;
        for (j = i; j > 0; j--)
          genpoly[j] = genpoly[j]
            ? genpoly[j - 1] ^ gexp[modnn(glog[genpoly[j]] + i)] : genpoly[j - 1];
        genpoly[0] = gexp[modnn(glog[genpoly[0]] + i)];
      }
      for (i = 0; i <= eccblkwid; i++)
        genpoly[i] = glog[genpoly[i]]; // use logs for genpoly[] to save calc step
  
      // append ecc to data buffer
      k = x;
      y = 0;
      for (i = 0; i < neccblk1; i++) {
        appendrs(y, datablkw, k, eccblkwid);
        y += datablkw;
        k += eccblkwid;
      }
      for (i = 0; i < neccblk2; i++) {
        appendrs(y, datablkw + 1, k, eccblkwid);
        y += datablkw + 1;
        k += eccblkwid;
      }
      // interleave blocks
      y = 0;
      for (i = 0; i < datablkw; i++) {
        for (j = 0; j < neccblk1; j++)
          eccbuf[y++] = strinbuf[i + j * datablkw];
        for (j = 0; j < neccblk2; j++)
          eccbuf[y++] = strinbuf[(neccblk1 * datablkw) + i + (j * (datablkw + 1))];
      }
      for (j = 0; j < neccblk2; j++)
        eccbuf[y++] = strinbuf[(neccblk1 * datablkw) + i + (j * (datablkw + 1))];
      for (i = 0; i < eccblkwid; i++)
        for (j = 0; j < neccblk1 + neccblk2; j++)
          eccbuf[y++] = strinbuf[x + i + j * eccblkwid];
      strinbuf = eccbuf;
  
      // pack bits into frame avoiding masked area.
      x = y = width - 1;
      k = v = 1;         // up, minus
      /* inteleaved data and ecc codes */
      m = (datablkw + eccblkwid) * (neccblk1 + neccblk2) + neccblk2;
      for (i = 0; i < m; i++) {
        t = strinbuf[i];
        for (j = 0; j < 8; j++ , t <<= 1) {
          if (0x80 & t)
            qrframe[x + width * y] = 1;
          do {        // find next fill position
            if (v)
              x--;
            else {
              x++;
              if (k) {
                if (y != 0)
                  y--;
                else {
                  x -= 2;
                  k = !k;
                  if (x == 6) {
                    x--;
                    y = 9;
                  }
                }
              }
              else {
                if (y != width - 1)
                  y++;
                else {
                  x -= 2;
                  k = !k;
                  if (x == 6) {
                    x--;
                    y -= 8;
                  }
                }
              }
            }
            v = !v;
          } while (ismasked(x, y));
        }
      }
  
      // save pre-mask copy of frame
      strinbuf = qrframe.slice(0);
      t = 0;           // best
      y = 30000;         // demerit
      // for instead of while since in original arduino code
      // if an early mask was "good enough" it wouldn't try for a better one
      // since they get more complex and take longer.
      for (k = 0; k < 8; k++) {
        applymask(k);      // returns black-white imbalance
        x = badcheck();
        if (x < y) { // current mask better than previous best?
          y = x;
          t = k;
        }
        if (t == 7)
          break;       // don't increment i to a void redoing mask
        qrframe = strinbuf.slice(0); // reset for next pass
      }
      if (t != k)         // redo best mask - none good enough, last wasn't t
        applymask(t);
  
      // add in final mask/ecclevel bytes
      y = fmtword[t + ((ecclevel - 1) << 3)];
      // low byte
      for (k = 0; k < 8; k++ , y >>= 1)
        if (y & 1) {
          qrframe[(width - 1 - k) + width * 8] = 1;
          if (k < 6)
            qrframe[8 + width * k] = 1;
          else
            qrframe[8 + width * (k + 1)] = 1;
        }
      // high byte
      for (k = 0; k < 7; k++ , y >>= 1)
        if (y & 1) {
          qrframe[8 + width * (width - 7 + k)] = 1;
          if (k)
            qrframe[(6 - k) + width * 8] = 1;
          else
            qrframe[7 + width * 8] = 1;
        }
      return qrframe;
    }
  
  
  
  
    var _canvas = null;
  
    var api = {
  
      get ecclevel() {
        return ecclevel;
      },
  
      set ecclevel(val) {
        ecclevel = val;
      },
  
      get size() {
        return _size;
      },
  
      set size(val) {
        _size = val
      },
  
      get canvas() {
        return _canvas;
      },
  
      set canvas(el) {
        _canvas = el;
      },
  
      getFrame: function (string) {
        return genframe(string);
      },
      //这里的utf16to8(str)是对Text中的字符串进行转码，让其支持中文
      utf16to8: function (str) {
        var out, i, len, c;
  
        out = "";
        len = str.length;
        for (i = 0; i < len; i++) {
          c = str.charCodeAt(i);
          if ((c >= 0x0001) && (c <= 0x007F)) {
            out += str.charAt(i);
          } else if (c > 0x07FF) {
            out += String.fromCharCode(0xE0 | ((c >> 12) & 0x0F));
            out += String.fromCharCode(0x80 | ((c >> 6) & 0x3F));
            out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));
          } else {
            out += String.fromCharCode(0xC0 | ((c >> 6) & 0x1F));
            out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));
          }
        }
        return out;
      },
      /**
       * 新增$this参数，传入组件的this,兼容在组件中生成
       */
      draw: function (str, canvas, cavW, cavH, $this, ecc) {
        var that = this;
        ecclevel = ecc || ecclevel;
        canvas = canvas || _canvas;
        if (!canvas) {
          console.warn('No canvas provided to draw QR code in!')
          return;
        }
  
        var size = Math.min(cavW, cavH);
        str = that.utf16to8(str);//增加中文显示
  
        var frame = that.getFrame(str),
          // 组件中生成qrcode需要绑定this 
          ctx = wx.createCanvasContext(canvas, $this),
          px = Math.round(size / (width + 8));
        var roundedSize = px * (width + 8),
          offset = Math.floor((size - roundedSize) / 2);
        size = roundedSize;
        //ctx.clearRect(0, 0, cavW, cavW);
        ctx.setFillStyle('#ffffff')
        ctx.fillRect(0, 0, cavW, cavW);
        ctx.setFillStyle('#000000');
        for (var i = 0; i < width; i++) {
          for (var j = 0; j < width; j++) {
            if (frame[j * width + i]) {
              ctx.fillRect(px * (4 + i) + offset, px * (4 + j) + offset, px, px);
            }
          }
        }
        ctx.draw();
      }
    }
    module.exports = { api }
    // exports.draw = api;
  
  })();